1. Field of the Invention
The subject invention relates to containers for dispensing liquid, creamy, pasty or like products, and more particularly, to improved containers including one-way valves and collapsible and/or squeeze tubes that maintain the product in an airless and/or sterile condition during repeated dispensing, and to related methods of making and using such containers and valve assemblies.
2. Background of the Related Art
Flexible tubes are used to store a variety of powder, liquid, gel, creamy and pasty products having a broad range of viscosities. Generally, the flexible tubes have a cover which is removed to expose a simple release aperture. As a result, low pressure is required to express the contents therein. Undesirable oozing and collection of product that can clog the release aperture is common. Moreover, when the traditional tube is opened, the contents are not only subject to the environment but a quantity of air is normally sucked into the tube. Hence, despite techniques for sterilizing foodstuffs and other products, even the use of preservatives cannot prevent degradation of many products, thereby limiting the shelf-life and range of products suitable for dispensing via tubes. For tubes which dispense multiple doses, even refrigeration after opening cannot prevent the subsequent degradation of the product. The perishable item still has a limited shelf life. In view of the above, one solution has been to provide sterile servings in smaller, portable quantities, such as individual serving packets of ketchup, mustard and mayonnaise.
Similarly, many cosmetic, dermatological, pharmaceutical and/or cosmeceutical products and other substances are packaged in dispensers or other containers that expose the product to air after opening and/or initially dispensing the product. As a result, such products must include preservatives in order to prevent the product remaining in the container from spoiling or otherwise degrading between usages. In addition, such products typically must be used within a relatively short period of time after opening in order to prevent the product from spoiling or otherwise degrading before use. One of the drawbacks associated with preservatives is that they can cause an allergic or an otherwise undesirable reaction or effect on the user. In addition, the preservatives do not prevent the bulk product stored within the open container from collecting, and in some cases, facilitating the growth of germs. Many such prior art dispensers expose the bulk product contained within the dispenser after opening to air, and thus expose the bulk product to bacteria, germs and/or other impurities during and/or after application of the product, thereby allowing contamination of the product remaining in the dispenser and spreading of the bacteria, germs or impurities with subsequent use of the product. For example, liquid lipstick is particularly poorly suited for dispensing by prior art containers. The liquid lipstick becomes contaminated, evaporates due to air passage losing moisture, and ultimately is unusable if not unsafe before complete utilization of the product. The tips become contaminated, dirty and sticky or crusty as well as allowing the lipstick to continue to flow when not being used.
In view of the above, several containers have been provided with closure devices such as one-way valves. One drawback associated with prior art dispensers including one-way valves is that the valves are frequently designed to work with mechanical pumps or like actuators that are capable of creating relatively high valve opening pressures. Exemplary dispensers of this type are illustrated in U.S. Pat. Nos. RE 37,047, 6,032,101, 5,944,702, and 5,746,728 and U.S. Publication Nos. US2002/0074362 A1, US2002/0017294 A1. Squeeze tube-type dispensers, on the other hand, are not capable of creating the necessary valve opening pressures, and therefore such prior art valves do not work effectively with squeeze tubes.
Accordingly, it is an object of the present invention to overcome one or more of the above-described drawbacks and disadvantages of the prior art.